Mt Hood

Expect slick conditions on all aspects early, with the potential for long sliding falls lingering on shaded slopes. Carry self-arrest tools and know how to use them if crossing steep, icy terrain. Sunny aspects will improve travel, but adjust your aspect or slope angle if surface snow starts to entrain.

Sunny skies, light winds, and temperatures in the low to mid-40s at ski area elevations all came together for the sun to soften W-SW-S-SE aspects on Monday. Snow quality drastically improved on sun-soaked aspects with 3-4" of ski penetration atop a firm crust in the White River Canyon. However, the surface snow was not prone to entrainment.

We also received reports of firm, scoured slopes at upper elevations on the north side of Mt Hood, with pockets of softer snow.  This fills in some uncertainty and suggests that surface conditions are broadly similar on the northern and southern halves of the mountain.

Tuesday should be similar to Monday, with light winds and freezing levels around the top of Mt Hood. The combination of slightly warmer temperatures Monday night and Tuesday would have us concerned if this were later in the year or if we hadn't been through multiple warm cycles without precipitation already this January. That said, keep your guard up for slopes where 6" of softened snow wants to entrain more snow on steep test slopes.

As this pattern continues, keep some things in mind:

• Long, sliding falls will continue to be your greatest mountain hazard. Expect surfaces to be the most firm during the early morning hours, with some softening in the sun as the day heats up. Pay close attention to aspect and sun angle as you plan your travel. Remember it doesn’t take much shade for surfaces to flash-freeze at the end of a January day. Having crampons, an ice axe, and the ability to use this gear properly will be absolutely necessary to navigate safely in our terrain.
• Wet snow is expected to form on SW-SE aspects as the day heats up. Fortunately, the snowpack is well adjusted to temperature fluctuations at this point, but an isolated wet loose avalanche can still occur. Adjust your plans and head to shadier slopes if you notice ski cuts triggering wet loose sluffs or if you find yourself sinking past your ankles in wet snow. 
• Triggering a wind slab is unlikely, but not impossible. On Saturday, forecasters observed the strong NE winds drifting snow onto the upper mountain, west aspects like the  Sandy Headwall and the Reid Glacier. If you find yourself traveling at the highest elevations, still be on the lookout for wind-stiffened slabs. Surface clues like softerpockets of snow overlying firm crusts, ripples, and dunes can help you anticipate where wind slabs may lurk. 
• Continue to use normal caution and best-practice backcountry travel techniques. Carry avalanche rescue gear and only expose one rider or climber at a time to steep, complex terrain. 

While not a problem right now, the upper snowpack continues to weaken during this prolonged period of high pressure. Snow surfaces vary widely between slick crusts, old wind-drifted snow, sastrugi, and even some softer, faceting snow on true northerlies in sheltered terrain. The distribution of weak snow surfaces varies, but below the surface plenty of faceted snow can be found, often sandwiched between crust layers. This structure is not currently an issue in most places, but it could be a different story once there is a slab above.

Even during long periods of high pressure, observations are key in producing a more accurate avalanche forecast. Let us know what you see by submitting a public observation here.